Sounds like a bug in the Matrix to me. It will probably be fixed in the next release.
I could be very wrong here, but would the conservation of energy, and the fact that eventually all the used energy eventually ends up as heat energy, mean that the only thing these wind mills could do is move heat from the area of the wind farm to the city or where ever the power is used? Perhaps there could be local changes between night and day but those would have to seem to cancel out beyond the transfer to the city. And the city (plus the heat in the electrical lines) would warm up by the exact amount of cooling at the wind farm?